This was the car that started the pony car craze, and it's been a consistent favorite for Ford collectors ever since. Good condition basic models of this generation are both affordable and collectible.
The original Mustang was offered as a notchback coupe or convertible starting in mid-1964. The slope-roofed fastback coupe arrived later in the 1965 model year. The base six cylinder engine and unmodified Falcon chassis and suspension delivered unremarkable performance, but available 260 and 289 V8 engines pumped up the volume. The Mustang's first generation saw several redesigns, starting in 1967, and again in 1969 and 1971.
Notable performance models in this era include the GT350, Shelby GT500, 428 Cobra Jet, Boss 302, Boss 429, and the Mach 1. Expect to pay more - in some cases a lot more - for any of these.